Effects of Nicotine and Nicotine Expectancy on Attentional Bias for Emotional Stimuli

INTRODUCTION: Nicotine's effects on mood are thought to enhance its addictive potential. However, the mechanisms underlying the effects of nicotine on affect regulation have not been reliably demonstrated in human laboratory studies. We investigated the effects of abstinence (experiment one), and nicotine challenge and expectancy (experiment two) on attentional bias towards facial emotional stimuli differing in emotional valence.

METHODS: In experiment one, 46 nicotine-deprived smokers were randomised to either continue to abstain from smoking or to smoke immediately before testing. In experiment two, 96 nicotine-deprived smokers were randomised to smoke a nicotinised or denicotinised cigarette and to be told that the cigarette did or did not contain nicotine. In both experiments participants completed a visual probe task, where positively-valenced (happy) and negatively-valenced (sad) facial expressions were presented, together with neutral facial expressions.

RESULTS: In experiment one there was evidence of an interaction between probe location and abstinence on reaction time, indicating that abstinent smokers showed an attentional bias for neutral stimuli. In experiment two there was evidence of an interaction between probe location, nicotine challenge and expectation on reaction time, indicating that smokers receiving nicotine, but told that they did not receive nicotine, showed an attentional bias for emotional stimuli.

CONCLUSIONS: Our data suggest that nicotine abstinence appears to disrupt attentional bias towards emotional facial stimuli. These data provide support for nicotine's modulation of attentional bias as a central mechanism for maintaining affect regulation in cigarette smoking.